Z

​Zero Tolerance:The standard to which U.S. beef processors must adhere when it comes to fecal and ingesta carcass contamination. In layman’s terms, no visible contamination is allowed on beef carcasses. (Executive Summary of the National Non‐Fed Beef Quality Audit, 1994. National Cattlemen’s Beef Association. Englewood, CO.)

Zona Pellucida:Shell surrounding the oocyte and embryo. In cattle, embryos hatch out of this shell 7–8 days after fertilisation

Zone of Thermoneutrality:The environmental temperature (about 65°F) at which heat production and heat elimination are approximately equal for most farm animals

Zoonosis:An infection of animals that can then infect human beings, for example, leptospirosis. The animal may, or may not, show any symptoms

Zoonotic:A term used to describe any disease or infection that is naturally transmissible from animals to humans

Zoonotic Diseases:Diseases which are communicable from animals to humans